MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Руководство по разработке, Страница: 539 / 860

Using explicit queries 539
Using explicit queries
In an explicit query, the Verity search engine literally interprets your search terms. The following
are two ways to perform an explicit query:
•
On a search form, use quotation marks around your search term(s).
•
In CFML, use
type=”explicit
” in the
cfsearch
tag.
When you put a search term in quotation marks Verity does not use the STEM operator. For
example, a search for “instructional”—enclosed in quotation marks, as shown in
“Preventing
stemming” —does not return files that contain instruct, instructs, instructions, and so on (unless
the files also contain instructional).
When you specify
type=”explicit
” the search expression must be a valid Verity Query
Language expression. As a result, an individual search term must be in explicit quotation marks.
The following table shows valid and invalid criteria.
Using AND, OR, and NOT
Verity has many powerful operators and modifiers available for searching (for more information,
see
“Operators and modifiers” on page 543 ). However, users might only use the most basic
operators—AND and OR, and the modifier NOT. The following are a few important points:
•
You can type operators in uppercase or lowercase letters.
•
Verity reads operators from left to right. The AND operator takes precedence over the OR
operator.
•
Use parentheses to clarify the search. Terms enclosed in parentheses are evaluated first;
innermost parentheses are evaluated first when there are nested parentheses.
•
To search for a literal AND, OR, or NOT, enclose the literal term in double quotation marks;
for example:
love “and” marriage.
Note: Although NOT is a modifier, you use it only with the AND and OR operators. Therefore, it is
sometimes casually referred to as an operator.
Attribute Effect
criteria=”government” Generates an error
criteria="'government'" or
criteria='"government"' Finds only government
criteria="<WORD>government"
Finds only government
criteria=”<STEM>government"
Finds government, governments, and governmenta
criteria=”<MANY><STEM>government" Finds government, governments, and governmental ranked
by relevance
criteria="<WILDCARD>governmen*" Finds government, governments, and governmental